Photoluminescence and Magnetism in Mn2+-Doped ZnO Nanostructures Grown Rapidly by the Microwave Hydrothermal Method

Zn1-xMnxO nanostructures were synthesized via the microwave-assisted hydrothermal method, which rapidly produces particles of controlled size and morphology. Samples were analyzed considering the effects of manganese ion concentration. XRD revealed that all samples had wurtzite-type structure with Mn2+ ions incorporated in the oxide lattice. UV-vis spectra showed absorption bands from the d-d transitions of Mn2+ ions. As the doping concentration increased, the value of the energy gap decreased, indicating intermediary energy levels within the band gap in the Mn-doped ZnO samples. All samples produced broadband photoluminescence (PL) emissions in the yellow-orange-red range. Additionally, the PL intensity decreased with Mn2+ ion incorporation into the ZnO lattice due to the creation of new recombination centers. Microscopy images showed that manganese in the ZnO matrix produced homogeneously distributed nanostructures. EPR results indicated two locations of Mn2+ ions in the ZnO lattice, lower concentrations in the core of the lattice and higher concentrations at the surface.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Rede Nanobiotec/BrasilRede Mineira de Quimica (RQ:MG)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG, BrazilUniv Fed Uberlandia, Inst Fis, LNMIS, BR-38400902 Uberlandia, MG, BrazilUniversidade Federal de São Paulo, Dept Ciencias Mar, BR-11030400 Santos, BrazilUniversidade Federal de São Paulo, Dept Ciencias Mar, BR-11030400 Santos, BrazilCNPq: 477150/2008-0FAPEMIG: APQ-01842-09Web of Scienc

Effect of Er3+ ions on the phase formation and properties of In(2)O(3)nanostructures crystallized upon microwave heating

Regular sized nanostructures of indium oxide (In2O3) were homogeneously grown using a facile route, i.e. a microwave-hydrothermal method combined with rapid thermal treatment in a microwave oven. The presence of Er3+ doping plays an important role in controlling the formation of cubic (bcc) and rhombohedral (rh) In2O3 phases. The samples presented broad photoluminescent emission bands in the green-orange region, which were attributed to the recombination of electrons at oxygen vacancies. The photocatalytic activities of pure bcc-In2O3 and a bcc-rh-In2O3 mixture towards the UVA degradation of methylene blue (MB) were also evaluated. The results showed that Er+3 doped In2O3 exhibited the highest photocatalytic activity with a photonic efficiency three times higher than the pure oxide. The improved performance was attributed to the higher surface area, the greater concentration of electron traps due the presence of the dopant and the possible formation of heterojunctions between the cubic and rhombohedral phases.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (Capes)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)FAPEMIGUniv Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG, BrazilUniv Fed Sao Paulo, UNIFESP, BR-09972270 Diadema, SP, BrazilUniv Estadual Paulista, Inst Quim, LIEC, BR-14800900 Araraquara, SP, BrazilUniv Fed Sao Carlos, INCTMN UFSCar, BR-13565905 Sao Carlos, SP, BrazilUniv Fed Sao Paulo, UNIFESP, BR-09972270 Diadema, SP, BrazilFAPEMIG: APQ-00988-13FAPEMIG: APQ-00330-14FAPEMIG: CEX - RED-00010-14Web of Scienc

Clinicopathologic features and outcome of mycophenolate-induced colitis in renal transplant recipients

Reports on the clinical course of mycophenolic acid (MPA)-related colitis in kidney transplant recipients are scarce. This study aimed at assessing MPA-related colitis incidence, risk factors, and progression after kidney transplantation. All kidney transplant patients taking MPA who had colonic biopsies for persistent chronic diarrhea, between 2000 and 2012, at the Kidney Transplantation Unit of Botucatu Medical School Hospital, Brazil, were included. Cytomegalovirus (CMV) immunohistochemistry was performed in all biopsy specimens. Data on presenting symptoms, medications, immunosuppressive drugs, colonoscopic findings, and follow-up were obtained. Of 580 kidney transplant patients on MPA, 34 underwent colonoscopy. Colonoscopic findings were associated with MPA usage in 16 patients. The most frequent histologic patterns were non-specific colitis (31.3%), inflammatory bowel disease (IBD)-like colitis (25%), normal/near normal (18.8%), graft-versus-host disease-like (18.8%), and ischemia-like colitis (12.5%). All patients had persistent acute diarrhea and weight loss. Six of the 16 MPA-related diarrhea patients (37.5%) showed acute dehydration requiring hospitalization. Diarrhea resolved when MPA was switched to sirolimus (50%), discontinued (18.75%), switched to azathioprine (12.5%), or reduced by 50% (18.75%). No graft loss occurred. Four patients died during the study period. Late-onset MPA was more frequent, and no correlation with MPA dose or formulation was found

Efficient Ni and Fe doping process in ZnO with enhanced photocatalytic activity: A theoretical and experimental investigation

Zn1-xNixO and Zn1-xFexO structures were synthesized by the microwave-assisted hydrothermal method. The best photocatalytic degradation of rhodamine B (RhB) and 4-nitrophenol (4-NP) were achieved by the Zn0.96Ni0.04O and Zn0.99Fe0.01O. The specificity of each dopant showed significance in the positions of the impurity energy levels, which ended up influencing the electron-hole separation and transport, as demonstrated by the photoluminescence emissions. The morphological analysis revealed that besides inhibiting the growth of particles, the incorporation of dopant ions into the ZnO lattice triggered a nucleation process, consequently changing their morphology. Density functional theory (DFT) calculations showed that the Fe3+ 3d orbitals generate energy levels below the conduction band (CB) while for Ni2+, the levels were found to be spread in a broad energy range above the valence band (VB). The synergistic effect of band gaps alteration, inhibition of electron-hole pair recombination and appearance of new trapping energy sites justifies the superior photocatalytic activity

Cardanol-derived AChE inhibitors: Towards the development of dual binding derivatives for Alzheimer's disease

Cardanol is a phenolic lipid component of cashew nut shell liquid (CNSL), obtained as the byproduct of cashew nut food processing. Being a waste product, it has attracted much attention as a precursor for the production of high-value chemicals, including drugs. On the basis of these findings and in connection with our previous studies on cardanol derivatives as acetylcholinesterase (AChE) inhibitors, we designed a novel series of analogues by including a protonable amino moiety belonging to different systems. Properly addressed docking studies suggested that the proposed structural modifications would allow the new molecules to interact with both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE, thus being able to act as dual binding inhibitors. To disclose whether the new molecules showed the desired profile, they were first tested for their cholinesterase inhibitory activity towards EeAChE and eqBuChE. Compound 26, bearing an N-ethyl-N-(2-methoxybenzyl)amine moiety, showed the highest inhibitory activity against EeAChE, with a promising IC50 of 6.6 \u3bcM, and a similar inhibition profile of the human isoform (IC50 = 5.7 \u3bcM). As another positive feature, most of the derivatives did not show appreciable toxicity against HT-29 cells, up to a concentration of 100 \u3bcM, which indicates drug-conform behavior. Also, compound 26 is capable of crossing the blood-brain barrier (BBB), as predicted by a PAMPA-BBB assay. Collectively, the data suggest that the approach to obtain potential anti-Alzheimer drugs from CNSL is worth of further pursuit and development

Estudo da curva de crescimento de ovinos Santa Inês Analysis of the growth curve of Santa Ines sheep

Utilizaram-se 7.271 registros de pesos do nascimento aos 196 dias de idade de 952 crias de ovinos Santa Inês, controlados de 1983 a 2000, com os objetivos de verificar, entre os modelos Brody, Von Bertalanffy, Logístico, Gompertz e Richards, aquele que melhor descreve a curva média de crescimento e avaliar a influência de efeitos de ambiente sobre os parâmetros estimados. Os parâmetros foram estimados usando-se o procedimento NLIN do SAS. Para verificar se uma única curva seria adequada para descrever o crescimento de machos e fêmeas, nascidos de partos simples ou duplo, aplicou-se um teste de igualdade de parâmetros de modelos não-lineares. Os cinco modelos ajustaram bem os dados de crescimento, entretanto, maior variação dos resíduos foi verificada para os modelos Brody e Logístico. Com base nos desvios médios absolutos dos resíduos, constatou-se que o modelo Gompertz apresentou ajuste médio ligeiramente superior aos modelos Von Bertalanffy e Richards. Machos e fêmeas, nascidos de partos simples e duplo, apresentaram padrões de crescimento divergentes. Os efeitos de grupos contemporâneos, tipo de nascimento e sexo foram importantes fontes de variação para os parâmetros A e K. A correlação estimada entre os parâmetros A e K foi negativa. Melhorias no manejo alimentar devem ser incrementadas, principalmente quanto ao armazenamento de forragem, visando diminuir os efeitos indiretos do clima, o que poderá refletir em menor variação na forma da curva de crescimento.<br>Records of 7,271 weights of 952 lambs measured from birth up to 196 days of age between 1983 and 2000, available from the Agricultural Research Corporation of Paraiba database, were used to model the average growth curve of Santa Ines sheep. The influence of environmental effects on the estimated parameters of the Brody, Von Bertalanffy, Logistic, Gompertz and Richards functions was evaluated using the NLIN procedure of SAS. The growth curve was well fitted by all models but larger residual variation was obtained by the Brody and Logistic models. According to the absolute average residual error, the Gompertz model showed a better fit than the models Von Bertalanffy and Richards. Growth curves differed for males and females, born from single and twin lambing. Contemporary group, type of birth and sex significantly affected the estimation of parameters A and K. The correlation between parameters A and K was negative. Improvements in feeding management and forage storage may decrease the indirect effects of climate and contribute to reduce variation in the growth curves